Brushless coolant pump and cooling system

Abstract

A liquid pump with a brushless motor constructed to be received within a liquid reservoir of a cooling system to deliver liquid coolant under pressure to a manifold assembly through which the coolant is discharged onto various electronic components to cool them. The pump has a pumping assembly, a rotor, a stator and an electronic control circuit which controls the operation of the pump and each of which is immersed in liquid coolant in the pump housing to cool them as the coolant flows through the pump. Further, because each component within the pump can be exposed to the liquid in the pump, no sealed enclosures are needed for the pump as a whole or for any component therein and the pump can be received directly in the reservoir.

What is claimed is:  
     
       1. A system to cool a plurality of electronic components comprising: 
       a reservoir containing a supply of a coolant;  
       a pump having a brushless motor driving a pumping assembly constructed and arranged to draw the coolant from the reservoir into the pump and to discharge the coolant therefrom under pressure, the brushless motor having a stator, a rotor received in the stator and connected to the pump, and an annular space between the rotor and stator, an electronic control circuit electrically connected to the pump motor and responsive to a control signal to drive the motor and thereby drive the pumping assembly to discharge the coolant under pressure to flow through the annular space in direct contact with the stator and rotor and over the control circuit in contact therewith; and  
       at least one manifold receiving the coolant under pressure downstream of the pump, stator, rotor, and control circuit and supplying the coolant under pressure to a plurality of outlets through which the coolant is discharged onto the electronic components.  
     
     
       2. The system of  claim 1  wherein the pump is disposed within the reservoir and the reservoir defines a substantially sealed enclosure. 
     
     
       3. The system of  claim 1  which also comprises a heat exchanger having an inlet in communication with the reservoir and an outlet in communication with the pump whereby the pump draws coolant from the reservoir through the heat exchanger and into the pump. 
     
     
       4. The system of  claim 3  wherein the heat exchanger is disposed externally of the reservoir. 
     
     
       5. The system of  claim 4  wherein the pump is disposed externally of the reservoir. 
     
     
       6. The system of  claim 1  which also comprises a nozzle connected to each outlet to atomize liquid discharged therefrom and produce a liquid film on the electronic components to more evenly cool them. 
     
     
       7. The system of  claim 1  which also comprises a second manifold upstream of the at least one manifold and having a plurality of outlets each communicating with a separate one of the at least one manifolds. 
     
     
       8. The system of  claim 1  wherein the pumping assembly is a gear rotor type pumping assembly having a pair of intermeshing gears. 
     
     
       9. The system of  claim 1  wherein the control circuit is at least partially coated with an epoxy material so that it is more durable when exposed to coolant. 
     
     
       10. The system of  claim 1  wherein the pump has a stator with a plurality of stator windings, a permanent magnet rotor operably coupled to the pumping assembly and received in the stator between the stator windings and the control circuit is responsive to a control signal to selectively sequentially energize the stator windings and create a rotating magnetic field to rotate the rotor and drive the pumping assembly, and the rotor, stator and control circuit are each in contact with the coolant in the pump. 
     
     
       11. The system of  claim 10  wherein the rotor comprises a plurality of permanent magnets providing at least four magnetic poles. 
     
     
       12. The system of  claim 11  wherein the rotor magnets are encased in a polymeric material. 
     
     
       13. The system of  claim 1  which also comprises a housing which carries the pumping assembly, the rotor, the stator windings and the control circuit with the rotor, stator windings and control circuit in fluid communication with the coolant discharged from the pumping assembly. 
     
     
       14. The system of  claim 3  wherein the heat exchanger comprises a coil through which the coolant from the reservoir is drawn into the pump and a fan associated with the coil directs a forced air current onto the coil to cool the coil. 
     
     
       15. The system of  claim 4  wherein the pump and the electronic components are disposed within the reservoir and the reservoir defines a substantially sealed enclosure. 
     
     
       16. A liquid pump comprising: 
       a housing;  
       a stator with plurality of stator windings received in the housing;  
       a magnetic rotor received in the stator between the stator windings and with an annular space between the rotor and stator;  
       a pumping assembly received in the housing and constructed and arranged to draw fluid therein and to discharge the fluid therefrom under pressure, the rotor being operably connected with the pumping assembly to drive it; and  
       an electronic control circuit electrically connected to the stator windings and responsive to an electric current to selectively sequentially energize the stator windings and create a rotating magnetic field whereby the rotating magnetic field causes the rotor to rotate and drive the pumping assembly and the fluid discharged under pressure flows through the annular space in direct contact with both the rotor and stator and over the control circuit and in contact therewith.  
     
     
       17. The pump of  claim 16  wherein the pump is disposed directly in a liquid reservoir. 
     
     
       18. The pump of  claim 16  wherein the pumping assembly is a gear rotor type pumping assembly having a pair of intermeshing gears. 
     
     
       19. The pump of  claim 16  wherein the control circuit is at least partially encapsulated in an epoxy material directly contacted by the fluid. 
     
     
       20. The pump of  claim 16  wherein the rotor comprises a plurality of permanent magnets providing at least four magnetic poles. 
     
     
       21. The pump of  claim 20  wherein the rotor magnets are encased in a polymeric material. 
     
     
       22. The pump of  claim 16  which also comprises a shaft upon which the rotor and the pumping assembly are journalled for rotation. 
     
     
       23. The pump of  claim 16  which also comprises a housing which carries the pumping assembly, the rotor, the stator windings and the control circuit with the rotor, stator windings and control circuit in fluid communication with the fluid discharged from the pumping assembly. 
     
     
       24. The pump of  claim 16  wherein the fluid is a dielectric fluid. 
     
     
       25. The pump of  claim 16  wherein the control circuit is coated with a dielectric material. 
     
     
       26. A liquid pump comprising: 
       a housing;  
       a stator with a plurality of stator windings received in the housing;  
       a magnetic rotor received in the stator between the stator windings;  
       a pumping assembly received in the housing and constructed and arranged to draw fluid therein and to discharge the fluid therefrom under pressure, the rotor being operably connected with the pumping assembly to drive it;  
       an electronic control circuit electrically to the stator windings and responsive to an electric current to selectively sequentially energize the stator windings and create a rotating magnetic field whereby the rotating magnetic field causes the rotor to rotate and drive the pumping assembly and the rotor, stator and control circuit are each in contact with the fluid in the housing; and  
       wherein the fluid is dielectric fluid and the control circuit is uncoated and is in direct contact with the dielectric fluid.